1. Field of the Invention
The present invention relates to an arrangement of a governor for controlling, in a transmission system extending from an engine of a vehicle to axles thereof, engine outputs in response to load torque generated through rotational resistance applied on running wheels.
2. Related Art
Rotational resistance applied on wheels of a running vehicle is reversibly transmitted through a transmission system extending from an engine to axles as torque acting to rotate an engine output shaft in a direction opposite to its rotational direction of driving (hereinafter referred to as xe2x80x9cload torquexe2x80x9d). This torque comes to load during driving the engine. A generally used means for controlling the engine output in correspondence with this load (that is, increasing the output in accordance with the amount of load) is an electronic governor for calculating the amount of load upon detection through an engine output revolution speed sensor or similar and performing control based on the calculated value. Japanese Patent Unexamined Publication No. 38934/2000 discloses an arrangement of a governor being more advantaged in view of costs wherein a mechanical load detecting means (sensor) is provided at some midpoint of a transmission system for detecting load torque generated in the transmission system when rotational resistance is applied on wheels of a vehicle.
It is an object of the present invention to provide a mechanical governor of load detecting type arranged in that it utilizes a mechanical load detecting means, which is provided at some midpoint of a transmission system extending from an engine to wheels, that is linked to an output adjusting means of the engine (e.g. throttle of a carburetor of a gasoline engine or a control rack/control sleeve that functions as a means for adjusting a plunger lead position of a fuel injecting pump of a diesel engine) through an appropriate link mechanism.
In arranging such a governor, the link mechanism of the present invention between the load detecting means and the output adjusting means is comprised by way of a link connecting between an engine output setting means such as an accelerator pedal and the output adjusting means. More particularly, the governor of the present invention is generally comprised of a system wherein the output adjusting means is displaced based on a set output value as set by the output setting means, and wherein the load detecting means, which position is defined by the set value of the output setting means, is further displaced to an output increasing side upon detection of load torque by the load detecting means.
The governor of the present invention is further arranged in that the output adjusting means is not operated to the output increasing side even upon detection of increase of load torque by the load detecting means when the output setting means is in a range from an initial position to a specified low output set region. With this arrangement, in case the operator eases operating force applied to the output setting means with the aim of ceasing accelerating operations or braking and returns the output setting means to its initial position or the specified low output set region, the output of the engine will be decreased as intended by the operator even though the load detecting means will detect increase in load torque when rotational resistance is applied on the wheels through braking.
The governor of the present invention is further arranged in that a response speed of the output adjusting means with respect to load detection of the load detecting means is increased with increases in set value as set by the output setting means beyond the low output set region, and control of increases in output is suitably performed in correspondence to load detection in both, low speed running and high speed running conditions.
For achieving the above actions, the governor of the present invention is comprised of a movable member being displaceable on a basis of a set value as set by the output setting means and being linked to the output adjusting means, the movable member being further connected to the load detecting means, wherein a position of the movable member defined by the set value set by the output setting means is further displaced upon detection of load torque by the load detecting means for further displacing the output setting means to an output increasing side. In this arrangement, the linkage between the load detecting means and the movable member is arranged with play such that the movable member will not be displaced even upon detection of load torque by the load detecting means when the output setting means is in the low output set region.
This play is further set to be decreased and finally vanished in accordance with increases of the set value set by the output setting means beyond the low output set region.
For achieving compactness and protection of the governor arrangement of the present invention, the movable member may be incorporated in a housing incorporating therein the transmission system.
The governor of the present invention is further arranged in that positional adjustment of the output adjusting means is performed by additionally accommodating a detected value of a revolution speed detecting means for detecting an engine output revolution speed, thereby eliminating excess increases in output revolution speed of the engine.
More particularly, the revolution speed detecting means for detecting an output revolution speed of the engine is comprised with a first movable member that is displaced in accordance with revolution speed detection. The first movable member is linked to the output adjusting means such that the output adjusting means is displaced to an output decreasing side accompanying increases in detected value of the revolution speed detecting means.
On the other hand, the above-described movable member, which is arranged to be displaced in one direction with increases in the set value set by the output setting means and which position as defined by the set value of the output setting means is further displaced in the one direction when load torque is detected by the load detecting means, is defined to be a second movable member. The first movable member and the second movable member are linked such that a displacement direction of the second movable member accompanying increases in the set value of the output setting means and the detected value of the load detecting means and the displacement direction of the first movable member accompanying increases in the detected value of the revolution speed detecting means are mutually opposite, wherein the first movable member is displaced upon displacement of the second movable member by an amount decrement by a displacement amount on a basis of detection of the revolution speed detecting means, and wherein positional control of the output adjusting means is performed based on the displacement of the second movable member.
An elastic member may be interposed between the first movable member and the second movable member to prevent damages on the first movable member through forcible pulling by the second movable member.
A play with similar actions as the above-described ones is provided also in this arrangement between the second movable member and the load detecting means.
The above and further objects, features and effects of the present invention will become more relevant from the following detailed explanations based on the accompanying drawings.